A dynamic message sign is a sign having a message that can be dynamically changed. Dynamic message signs may be used to publicly display information and/or graphics. For example, dynamic message signs are used on roadways to alert motorists of traffic information, and as commercial signs, e.g., to advertise business or product information. Dynamic message signs may be connected to a controller for controlling messages displayed by the sign. Typically, a controller is a computing device having an interface for communicating with the sign.
Dynamic message signs may also include multiple individual display units, that each produce part of the overall display. In a dynamic message sign having multiple display units, the controller may communicate with each display unit to send information to refresh the display units.
During operation, dynamic message signs may fail to communicate properly with the controller. This failure may be caused by a disruption in the communication system or, in the case of a dynamic message sign having multiple display units, by a damaged or malfunctioning display unit. Alternatively, the data sent to the dynamic message sign panel by the controller may become corrupted. Conventional dynamic message signs are not configured to detect or correct communication and/or data errors.